1. Field of the Invention
The present invention relates to a gel and various articles of manufacture such as a cushion liner with fabric on the inside and/or outside thereof, cushion locking liner with added-on metal threaded insert, open-ended cushion knee or elbow sleeve, cushion fabric and cushion flat sheet all useful for increasing the comfort of the wearer. Also described is a sleeve member, and reinforced sleeve member for enclosing an amputation stump, preferably, a cushioned sock for use by, e.g., below-knee (BK) or above-knee (AK) amputees. The sleeve member and cushioning devices are preferably provided in a contoured form fit configuration which, when worn, comes up over the limb and adapts to a right or left side bias of the bony prominence of the residuum (stump) or are provided in simple tube (i.e., tube-sock) shape with various optional cushioning. Cushioning material may optionally be provided on the inside and/or outside of the invention sleeves, liners and sheet to minimize the discomfort of, e.g., an orthotic device, such as a knee brace, or a prosthetic device, such as an artificial arm or leg. In a preferred embodiment, the cushioning material is adjusted in thickness and has a non-uniform thickness over the article surface. In another a preferred embodiment the sleeves and liner have cushioning material in a recessed achilles configuration: the cushioning material does not contact the wearer at an upper posterior (i.e., knee crease), or upper anterior (i.e., elbow crease, etc.) portion of the limb or residuum, or minimally contacts the wearer at these positions, while providing cushioning, etc. to the knee or elbow due, e.g., to the thinning of cushioning material, even while the line, sleeve, etc. comes up over the joint. For example, the cushioning material can be thinner in these areas than in other places. In special applications, such as for Symes amputations, a thinner coating of gel at the distal end of a sleeve or liner can be used.
2. Discussion of the Background
For at least the past 80 years amputees have worn tubular socks over their residual limb. Cotton, wool and cotton-wool blends have typically been used. More recently, with the advent of synthetic materials, nylon and other textiles, including some with a measure of elasticity, have also been utilized.
In a typical lower limb prosthesis an amputee's stump tends to “piston” in the socket: during ambulation the stump will come up in the socket of the prosthesis until the attaching means holding the prosthesis to the wearer cause the prosthesis to lift with the stump. On the way down, air may be trapped between the residuum and stump sock, or between the prosthesis socket and sock, or between a socket liner and a sock.
With wool and cotton socks which tend to breathe and which are not airtight this pistoning effect is not a major problem with regard to the generation of sound effects. Since wool and cotton tend not to tightly form fit a residuum, however, the amputee typically packs a material around the residuum once it is placed into the prosthetic device or adds additional socks to increase thickness or puts on thicker socks in order to provide necessary fit. However, for socks which do not breathe and which are made from, e.g., polymeric material, a problem occurs when the residuum pistons in the prosthetic device: terrific sound effects such as sucking and gurgling noises are generated which are obtrusive and inappropriate, often embarrassing the wearer. In addition, such air pockets produce non-uniform pressures and loading discontinuities on the skin, irritating it.
Finally, many amputees experience a swelling of the stump. When the residuum is in a prosthetic socket the stump tends to contract significantly, and when taken out of the socket the stump tends to expand within minutes of removal. This expansion and contraction of the residuum contributes to the development of air pockets and the generation of obtrusive noises since a sock which may have provided a comfortable fit on the expanded stump becomes a loose fit with air pocket opportunities when the residuum is placed inside the prosthetic socket. In addition, and over time, an amputee's residuum tends to adjust in size, usually shrinking. As these changes occur they increase the tendency for the pistoning effect, described above, to occur. In addition to the embarrassment caused by the sound effects generated by pistoning, cushioned socks which allow or promote air pocket formation quickly wear out and, if not replaced often, lead to lesions, etc. on the residuum.
Currently available cushioned residuum socks are tubular or conical and do not provide a form fit on an amputee's residuum. Regardless whether such socks are provided with internal and/or external cushioning material they fail to avoid air pockets. While a stump may generally have a roughly conical or cubical shape there are invariably recessed areas on, e.g., the medial side of the prominent tibia bone. Generally, on a below knee, left side residual limb the recessed area will be predominantly on the right side of the tibia bone. There is also typically a smaller recessed area on the left side. For right side residual limbs the predominant recessed area is on the left side of the bone, with smaller recessed areas on the right side. Usually the greatest recess occurs immediately below the patella, on either side. In addition, left side amputees typically have a right side bias to the bony prominence of the below knee stump, and right side amputees have a similar bias to the left side. Conventional tubular or conical elastic socks simply cannot account for these several variable conditions without using extremely high levels of elastic tension which compress the outer-most points along the stump's circumference, causing discomfort and a non-uniform fit.
Amputees typically attach a prosthetic limb to their residual limb by means of a rigid socket, liner, and a suspension means. The rigid socket is often custom fabricated to match the shape of the intended user's residual limb and may be made of thermoplastic or fiber-reinforced thermoset materials, but can also be made from wood, metal, etc. Since such hard materials are generally uncomfortable when in intimate with the skin over long periods of time, especially under load bearing conditions, liners and/or prosthetic socks are often used as interface members between the hard socket and the residual limb to increase comfort. Such liners are generally of the open cell foam type, such as Pelite or Kemblo, but may also be made of silicon, urethane, etc. type materials. See, for example, U.S. Pat. No. 5,258,037 and U.S. Pat. No. 5,376,132, both incorporated herein by reference. Prosthetic socks, as mentioned above, may be made of wool, cotton, synthetic materials, etc, and amputees tend to prefer liners and socks which are easily changed to facilitate cleaning, to accommodate volume changes in the residual limb, or to accommodate different user activities.
Suspension systems which help to hold a prosthetic limb in place may or may not be an integral part of the rigid socket and/or liner. Examples of suspension systems include supracondylar or waist belt, joint and corset systems, neoprene or latex sleeves, socket ears which grip the condyles, suction or pin and lock systems such as those where the pin is attached to a liner and the lock is attached to a hard socket, etc. Examples of typical suspension systems may be found in U.S. Pat. No. 4,923,474, U.S. Pat. No. 4,923,475, U.S. Pat. No. 5,007,937, U.S. Pat. No. 5,108,456, U.S. Pat. No. 5,201,773, U.S. Pat. No. 5,201,774, U.S. Pat. No. 5,246,464, U.S. Pat. No. 5,263,923, U.S. Pat. No. 5,314,497, U.S. Pat. No. 5,387,245, U.S. Pat. No. 5,376,131 and U.S. Pat. No. 5,405,405, all incorporated herein by reference.
However, and as is clear from the above description of the prior art, all current interfaces for use between an amputee's residual limb and a prosthetic device suffer from drawbacks which may include custom fabrication (and corresponding long lead times), high cost, low durability, space requirements (too long, too high profile, etc.), noise due, for example, to air pockets forming between the liner and the residual limb, skin irritation, restricted joint range of motion, lack of accommodation of stump geometry changes, objectionable odors, discoloration, inadequate comfort, etc.